1. Description of Related Art
Football, also known as soccer is a team sport played between two teams, of 11 players each, and is widely considered to be the most popular sport in the world. It is a ball game played on a rectangular grass field with a goal at each end. The object of the game is to score by maneuvering the ball into the opposing goal. The predominant feature of the sport is that no players other than the goalkeepers may use their hands or arms to propel the ball and goalkeepers can only use their hands on the ball in their goalkeeping area. The winner is the team who score the most goals by the end of the match.
Tennis is a game played between either two players (“Singles”) or two teams of two players (“Doubles”). Players use a stringed racquet to strike a hollow rubber ball covered with felt over a net into the opponent's court. In some places tennis is played on a grass court and called lawn tennis to distinguish it from court tennis.
Volleyball is a sport in which two teams separated by a high net use their hands, arms, or (rarely) other parts of their bodies to hit a ball back and forth over the net. Each team is allowed three hits to get the ball over the net to the other team. A point is scored if the ball hits the ground in the opponents' court, if the opponents commit a fault, or if they fail to return the ball properly.
It is desirable for a ball game field having simpler settings within modest cost and a method of playing the game with unique rules to improve body coordination and to promote the nimbleness of the parts of human body other than the hand.